From db66e0b8966dbe6c43ff9db6dbefb8bad5e176df Mon Sep 17 00:00:00 2001
From: Mohamed EZ-ZARGHILI <mohamed.ezzarghili@gmail.com>
Date: Sat, 23 Dec 2017 17:48:22 +0000
Subject: [PATCH] First release

---
 README.md    | 56 ++++++++++++++++++++++++++++++++++++-
 recaptcha.go | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 134 insertions(+), 1 deletion(-)
 create mode 100644 recaptcha.go

diff --git a/README.md b/README.md
index 78bf4db..aec97d0 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,56 @@
 # recaptcha-go
-Google recaptcha implementation in golang
+
+Google reCAPTCHA v2 form submittion in golang
+
+## Usage
+
+Install the package in your environment
+
+```bash
+go get github.com/ezzarghili/recaptcha-go
+```
+
+To use it within your own code
+
+```go
+import "github.com/ezzarghili/recaptcha-go"
+func main(){
+    recaptcha.Init (recaptchaSecret) // get your secret from https://www.google.com/recaptcha/admin
+}
+```
+
+Now everytime you need to verify a client request use
+
+```go
+success, err :=recaptcha.Verify(recaptchaResponse, ClientRemoteIP)
+if err !=nil {
+    // do something with err (log?)
+}
+// proceed with success (true|false)
+```
+
+or
+
+```go
+recaptcha.VerifyNoRemoteIP(recaptchaResponse)
+if err !=nil {
+    // do something with err (log?)
+}
+// proceed with success (true|false)
+```
+
+while `recaptchaResponse` is the form value with name `g-recaptcha-response` sent back by recaptcha server and set for in the form when user answers the challenge
+
+Both `recaptcha.Verify` and `recaptcha.VerifyNoRemoteIP` return a `bool` and `error` values `(bool, error)`
+
+Use the `error` to check for issues with the secret and connection in the server, and use the `bool` value to verify if the client answered the challenge correctly
+
+### Issues with this library
+
+If you have some problems with using this library, bug reports or enhancement please open an issue in the issues tracker.
+
+### License
+
+Let's go with somehting permitive should we ?
+
+[MIT](https://choosealicense.com/licenses/mit/)
\ No newline at end of file
diff --git a/recaptcha.go b/recaptcha.go
new file mode 100644
index 0000000..09b27be
--- /dev/null
+++ b/recaptcha.go
@@ -0,0 +1,79 @@
+package recaptcha
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"time"
+)
+
+var recaptchaSecret string
+
+const reCAPTCHALink = "https://www.google.com/recaptcha/api/siteverify"
+
+type reCHAPTCHRequest struct {
+	Secret   string `json:"secret"`
+	Response string `json:"response"`
+	RemoteIP string `json:"remoteip,omitempty"`
+}
+
+type reCHAPTCHResponse struct {
+	Success     bool      `json:"success"`
+	ChallengeTS time.Time `json:"challenge_ts"`
+	Hostname    string    `json:"hostname"`
+	ErrorCodes  []string  `json:"error-codes,omitempty"`
+}
+
+// Init initialize with the reCAPTCHA secret optained from https://www.google.com/recaptcha/admin
+func Init(ReCAPTCHASecret string) {
+	recaptchaSecret = ReCAPTCHASecret
+}
+
+// Verify returns true if the client answered the challenge correctly and have correct remoteIP
+func Verify(challenResponse string, remoteIP string) (bool, error) {
+	body := reCHAPTCHRequest{Secret: recaptchaSecret, Response: challenResponse, RemoteIP: remoteIP}
+	return confirm(body)
+}
+
+// VerifyNoRemoteIP returns true if the client answered the challenge correctly
+func VerifyNoRemoteIP(challenResponse string) (bool, error) {
+	body := reCHAPTCHRequest{Secret: recaptchaSecret, Response: challenResponse}
+	return confirm(body)
+}
+
+func confirm(recaptach reCHAPTCHRequest) (Ok bool, Err error) {
+	if recaptach.Secret == "" {
+		Err = fmt.Errorf("recaptcha secret has not been set, please set recaptcha.Init(secret) before calling verification functions")
+		return false, Err
+	}
+	// Go http client does not set a default timeout for request, so we need
+	// to set one for worse cases when the server hang, we need to make this available in the API
+	// to make it possible this library's users to change it, for now a 10s timeout seems resonable
+	netClient := &http.Client{
+		Timeout: 10 * time.Second,
+	}
+	jsonValue, _ := json.Marshal(recaptach)
+	response, err := netClient.Post(
+		reCAPTCHALink, "application/json",
+		bytes.NewBuffer(jsonValue),
+	)
+	if err != nil {
+		Err = fmt.Errorf("error posting to recaptcha endpoint: %s", err)
+		return false, Err
+	}
+	defer response.Body.Close()
+	resultBody, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		Err = fmt.Errorf("couldn't read response body: %s", err)
+		return false, Err
+	}
+	var result reCHAPTCHResponse
+	err = json.Unmarshal(resultBody, &result)
+	if err != nil {
+		Err = fmt.Errorf("invalid response body json: %s", err)
+		return false, Err
+	}
+	return result.Success, nil
+}